Method of producing incandescent mantles.



UNITED STATES PATENT orrion.

comm]: Rrormnn noun, or simian, GERMANY, Ass'ronon T0onaormm-onsntnsonarr M; B. 11., or BERLIN, GERMANY.

METHOD OF PRODUCING INCANDESCENT MANTLES.

No Drawing.

Patented Oct. 18, 1910,

To all whom it may concern:

Be it known that I, CONRAD RICHARD BoHM, a citizen of the Empire ofGermany, residing at Berlin, in the Empire of Germany, have invented anew and useful Method of Producing Incandescent Mantles, of which theiollowing is a specification.

My invention relates to improvements in known methods of preparing tubesmade from artificial silk, for producing incandescent mantles possessingnot only a high degree of strength and durability, but also a uniforni-iluminating power, so ithat'the manufacture of these incandescent mantleson a large scale is rendered easy and possible.

For some years past endeavors have been -made to us,e tubes made fromfabric of artificial silk fo'r the production of incandescentmantleg'smcethe.artificial silk presents certain-advantages over cotton,ramie, etc, (see for-instance Journal f'iir GasbeZeuch/t ung und.

' Wasseroersor Mtg, 1897; 'vblume 40, page 34:3; 1902, V0 ume-45,-pae232; 1908', volume 46, page 11; and 1906, v0 ume49, page 765). H0wever,-th'e artificial silk, owing to its peculiarf-natur'e, presents at thesame time con- "siderable dilfi'cultie', which require to be overcome. i

It has been roposed to soak the tubes pregnated' wit solutions ofnitrate of thoriurn and cerium in an alkaline liquid, for instanceammonia, so as to turn the nitrates of- 'the 'rare earthsjintohydroxide, but'this methodis objectionable for the following reasons:-The tubes so prepared and containing hydroxide will, after they havebeen dried, burnt, and cal'jcined,'be turned" into ashy skeletons ofcomparatively granular and hard oxids, which skeletons are certainlyurable, and not sensitive,'but present the de-- feet, that they consumeconsiderably more gas than thedrdinary incandescent mantles. Others havesubstituted for the alkaline aid 9. solution of peroxid of hydrogen,

wliereby incandescent mantles can hepro duced which are very soft,elastic and durable in the highest degree. However, it is extremelydi-flicult to produce by this method mantles of a uniform lighting werand this for the reason, that the hy rogen peroxid canturn the nitrateof thorium into a combination insoluble in water; viz.

peroxid ofthorium, which remains in the tube while thenitrate ,ofceriumis not altBI'Gli at. all, so that it is extracted the tube during thetreatment. It is true, that this drawback can be somewhat reduced in;

the manner, that the percentage of the nitrate of'c'erium is increased,say from 1%to'. 5%, and 1s added to amore concentrated solution ofhydrogen peroxid, or that an empirical excess 0 cerlurn is added to theconcentrated solution of-hydrogen peroxid', which solution in both casescontainsfrom 8 i to 10% instead of 3% of h drogenperoxidi Then there.will be a surp us of nitrate-of cerium in the tube, which surplusis'more on less removed durin the treatment, so that the percentage of te cerium in proportion;-

to the thorium in the finished mantle may be nearly correct. thequantity of cerium contained in the bath of hydrogen peroxid willnecessarily vary the illuminating power of the'incandescent mantledepend u However, it is obvious, that it-is evident, thatit is notpossible to pro-' duce by this method on a large scalejinjcan descentmantles of the same illuminating:

ower and color of 1i ht, as the latterwiljl be influenced by the eastvariat1on-in-the.

percentage of cerium. v 1

My invention relatesto-an improvement in the last namedmethod,;vvhereby' the. said. serious drawback is avoided; i, l l

The improvement consists ill-using in ad dition to the peroxid ofhydrogen oneyofisuch substances, which in conjunction with theperoxidjofhydrogen render the resultfi i ing cerium combinationinsoluble in water without in the least impeding the fol-ma! tion of aninsoluble thorium combination" under-the action of the peroxid ofhydrogen;

The mixthre of hydrogen peroxid and any of the said substances thereforeproduces an.

simultaneous and unifor separation and:'

de osition of thorium an 'cerium in the I tu tween the thorium and t ecerium gin-the.

Thereby a constant proportion ice-j;

finished mantle is guaran eed, and'ith'ejso f improved method permits itto manufaea,

ture on a lnr e scale mantles, which possess Such substances asmentioned abovear'e' various organic acids and their saltsa- I will- 1 Tname a few of them: Acetates in "the presence of peroxid of hydrogencan, senititte 'oerium' in a form which'is insolu'lofii'n bination atthe same time.

the tubes impregnated with solutions of .gthorium and cerium through abath of 3% ing, as usual, the incandescent mantles pos Qses'smg auniform the desired eifect:

. metals which are insplublein water. From .01: anyqofits salts in placeof the acetate for 1 acid, etc, and any suitable base can preci icase Irecommend to more or less neutralize I F-ormic acid, malic acid andother simiacetateand' the lactic acid, of any of them f said saltsshoirld be so chosen, that the salts 'i'l process dui mg t fSesl as theyseparating the cerium from the other rare earths. I have discovered,that the acetates. when added to the peroxid of hydrogen do not hinderthe precipitation of the thorium combination. A solution of 3% ofhydrogen peroxid and of from 6%,130 10% of any acetate is capable ofprecipitating both the thorium combination and the cerium com- Itherefore pass pero rid of hydrogen to which from 6% 1 07 of any acetateis added, for pro cing bydrying, burning off, andcalcin illuminatingpower and color of light. .It is to beremarked, howeter, that in thismethod free acids must be avoided as much as possible, so as to liinsureLactic acid addedhto the bath of peroxid of hydrogen Will alsd produce,together with theilatter, combinations o,f-cerium, thori um and otherrare earth 6% to 10% of lactic acid or any of its salts should be added'o the. solution of 3% of hydrogen peroxid for producing the said effect.therefore mayuse thelactic acid the production of incandescent antles ofa! similar iexcelle'nt kind. In thi' case. also as :before free acids'must be avoidedas much as possible.

laifa cids show a similar'behavior to the if from 5% to is added to thesolution 0 3% ofhydro en peroxid,'but the for-mic and'jthemfiic acid arecapable of .preat rare earthsfrom weak-acidsy,- suc as for examleac'etic acid. Any fzthe-salts formed of? orrhictizc'id, or, malic tatethe rare: earths from any acid. In t isthe' free acid in proportion tothe organic acid used. The

bases used for forming the" produced are capable of'bein easil removedfrom the tube of fabric, be: it by washing, or in a subsequent stage ofthe the burning oil or calcina- Va oration or disintegration. For Earammoniacombinations, in so do'not disturb the reaction. The method ofproducing the incandescent mantles from tubes-of artificial' silk maytion by cimng them.

otherwise be as usuansay as follows: The tubes of fabric are firstimpregnated with solutions of nitrates or other salts of thorium andcerium as'jus'ual, then dried, next impregl'iated with hydrogen peroxidto which a substance of the kind described above has been added,thereupon washed, if necessary, dried, burnt and calcined. Theimpregnation of the tubes with hydrogen peroxid and the substancementioned may be effected by passing the tubes several times through abath containing a-solution of 3% of hydrogen peroxid to which from. 6%to 10% of or of lactic acid or of any of its salts, or from 5% to 10% offormic acid, or malic acid or other similar acid, or of any-of theirsalts are added, the bath being heated up to from 25 to 35 c'entigrade.

In former methods only a solution of peroxid of hydrogen is employed forthe bath, through Which'the tubes are passed. As the peroxid of hydrogencan turn only the nitrate of thorium into a combination insoluble, inwater, it follows, that of the nitrates of the two rare earth metalscontained in the tubes that of the cerium re mains unaltered and can beextracted from the tube during the treatment, so'that the quantity ofcerium contained in the tube will vary and consequently it is impossible'to produce on a large scale incandescent mantles of a uniform qhality,as already mentioned above. By my new method, however, where for thebath the solution of a m1Xture of hydrogen; peroxid and anyof thementioned substances is employed, the important efl'ect'is obtained,that the simulnot be extractedtheiefrom during the treat- I renderedpossible,

ment or by subsequentwashing, so that the proportion between thethorium] and the cerium will remain constant for all gof; the

finished mantles. This is the tant, as it is possible to adoptvantageous proportion, of cerium and" 100 parts by Weight of thorium. v

I claim:

1; The method of producing incandescent mantles, which consistsinimpregnating the tubes of fabric with solutions ofsalts of thoriumandcerium, then-drying them, next passing them several times through a bathconsisting of a solution of hydrogen peroxid and of a sub anoecontaining the radical of an organic acid, whereby the salts ofthorium'and-cerium are simultaneously and independently turned intocombinations of thorium and cerium both insoluble in water, thereupondrying, burning, and calmore importhe most ad f viz. 1 part by weightacetate of ammonium or a similar acetate 2. The method of producingincandescent mantles, which consists in impregnating the tubes made fromfabric of artificial silk with solutions of salts of thorium and cerium,

then drying them, next passing them several times through a bathconsistm of a solution ot'hydrogen peroxid and o? a substancecontaining1 the radical of an organic acid, whereby t esalts of thoriumand cerium are 0 simultaneously and independently turned intocombinations of thorium and cerium both insoluble in water, thereupondrying, burning, and calcining them. v

The method of producing incandescent mantles, which consists inimpregnating the tubes of fabric with solutions of salts of thorium andcerium, then drying them; next passingthem several times through a bathconsisting of a solution of hydrogen peroxid and of a substancecontaining the radical of an organic acid, whereby the salts of thoriumand cerium are simultaneously and I independently turned intocombinations of thorium and cerium both insoluble in water, thereuponwashing, drying, burning, and calcining them. v

4. The method of producing incandescent mantles, which consists inimpregnating the tubes made from fabric of artificial silk withsolutions of salts of thorium and cerium, then drying them, next paingthem several times through a bath consistin of a solution of hydrogenperoxid and o a substance containing the radical of an 'organic acid,whereby the salts not thorium and cerium are simultaneously andindependently turned into combination of thorium and cerium bothinsoluble in water, thereupon washing,

drying, burning, and calcining them. CONRAD RICHARD Witnesses:

HENRY HAsrEn, Wownman HAUPT.

